Safety syringe

ABSTRACT

A syringe apparatus and process for using the same is provided, the syringe apparatus having a barrel, a plunger movable within the barrel, a needle assembly attached to an end of the barrel and having a passageway therethrough, a deformable base positioned within the barrel, flexible supports included on the deformable base, a spring within the passageway of the needle assembly, a hollow needle passing through the passageway, an enlarged head on the needle, and a rupturable web on an end of the plunger, whereby when the plunger moves through the barrel toward the needle assembly, a fluid can be moved from the barrel through the hollow of the needle, and continued movement of the plunger flexes the supports and moves the deformable base downwardly until such time a sufficient force is imparted to the rupturable web by the enlarged head to tear the web, the deformable base then releasing the needle due to force applied by the spring to project the needle into the interior of the plunger. Seals are provided for making a liquid impervious seal on both ends of the syringe after the needle is retracted. The seal on the end left open by needle retraction is a closing member which can be used to seal off the opening without placing a user&#39;s hands in front of the opening. The syringe includes indicia that is revealed upon needle retraction to label the syringe as a biohazard. A syringe apparatus using a deformable base, enlarged needle head and needle assembly of an alternative embodiment is also provided wherein sacrificial supports in the needle assembly are utilized and severed by the deformable base.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application Ser. No.09/593,974 filed on Jun. 13, 2000, which was a continuation-in-part ofU.S. application Ser. No. 08/359,001 filed on Dec. 16, 1994 which was acontinuation of Ser. No. 07/813,115 which was filed on Dec. 23, 1991,now U.S. Pat. No. 5,211,629.

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to the art of syringes and moreparticularly to a syringe which reduces the likelihood of unintentionalpuncture or pricking of human skin. In recent history, the transmissionof contagious diseases, particularly those brought about exclusively bythe co-mingling of human body fluids, has been of great technologicalinterest. One of the particular problems has been associated with theuse and disposal of hypodermic syringes, particularly among healthcareprofessionals. There have been various devices developed for thedestruction of the needles or cannula used in such syringes. Additionaldevices have been developed for capping of syringes which attempt tominimize the likelihood of accidental puncture. The accidental punctureor pricking of a finger, or any other part of the body, after thetreatment of a patient with a contagious disease, particularly a deadlycontagious disease, results in a high likelihood of transmission of thatdisease. Various syringes have been developed in the prior art toattempt to minimize the likelihood of accidental puncture after patienttreatment.

[0003] One such device is described in U.S. Pat. No. 4,973,316 to Dysarzwherein a needle is retracted into the barrel of the syringe after theuse thereof. Another such device is described in U.S. Pat. No. 4,921,486to DeChellis, et al. One of the earlier patents in this regard was U.S.Pat. No. 2,460,039 issued to Scherer, et al.

[0004] Other references disclosing devices relating to needle retractionin a syringe include U.S. Pat. Nos. 4,9,94,034 to Botich et al,4,838,869 to Allard, and 5,114,410 to Batlle, GB 2 197 792 to Powers etal., WIPO 90/06146 to Nacci et al., and WIPO 90/03196 to Utterberg etal. While all such devices seek the same goal of preventing accidentalpuncture, considerable room for improvement exists.

SUMMARY OF THE INVENTION

[0005] It is thus an object of this invention to provide a novelhypodermic syringe which minimizes the likelihood of accidentalpuncture.

[0006] It is a further object of this invention to provide such asyringe which, after utilization, isolates the used needle so as torender such needle harmless, and automatically indicates that thesyringe represents a biohazard.

[0007] It is a further and more particular object of this invention toprovide such a hypodermic syringe which is operable utilizing only onehand.

[0008] It is a further and yet more particular object of this inventionto provide such a syringe which automatically, upon the end of aninjection, retracts its needle to prevent its reuse, while sealing theneedle within the body of the syringe to prevent leakage of residualfluids.

[0009] It is a further object of the invention to provide a simpledevice, which is manufacturable in high volumes.

[0010] These as well as other objects are accomplished by a hypodermicsyringe having a barrel with a plunger movable therein to inject a fluidthrough a hollow needle thereof. A hollow needle is housed in apassageway within a needle assembly. Positioned between the passagewaywithin the needle assembly and a shelf on an internal wall of thesyringe barrel is a deformable base, with integral flexible supports.The deformable base forms a liquid tight seal with the barrel, at theneedle end of the barrel. The deformable base houses an enlarged head ofthe needle which enlarged head is in contact with energy storage meanswithin the passageway in the needle assembly. The plunger has a thin,rupturable web on an end thereof which is part of a boot covering theend of the plunger, the boot, including the web, being liquidimpermeable for forcing a liquid from the barrel upon movement of theplunger. Upon completion of an injection, the boot-covered plungercontacts the deformable base, and upon application of force at theplunger, moves such base downward. Continued application of force causesthe flexible supports to flex and move over the needle assembly,permitting the deformable base to move the enlarged head of the needledownward until further movement of the enlarged head is blocked by theneedle assembly. With the enlarged needle head blocked by the needleassembly, continued force at the plunger causes the deformable base tomove around the enlarged needle head. As the deformable base movesaround the needle assembly, the enlarged needle head begins to protrudefrom the deformable base and come into contact with the web on the bootof the plunger. Continued force causes the enlarged needle head to tearthe web of the boot, positioning the enlarged needle head just inside ahollow portion of the plunger. The torn portion of the web creates aflap just inside the hollow plunger. As the plunger moves the deformablebase still further, the enlarged needle head looses contact with thedeformable base, which triggers a release of energy from the energystorage means in the passageway, projecting the needle with its enlargedhead into the hollow portion of the plunger. Once inside the plunger,the needle is trapped by its enlarged head behind a flexible catchwithin the plunger. Final movement of the plunger causes the plunger tobecome substantially locked in the barrel and causes a liquid tight sealto be created between the plunger and the syringe body. A closing memberplaced on the front of the needle assembly completely seals the syringeto prevent residual fluids from escaping. Completion of the needleretraction also automatically highlights an indicia such as a biohazardlabel which alerts persons handling the device that the syringe has beenused and represents a potential biohazard.

[0011] In an alternative embodiment of the syringe according to thisinvention, a barrel, needle assembly, needle head, and deformable baseof different structures than above are utilized wherein the deformablebase is positioned between sacrificial supports in the needle assemblyand an internal wedged end of the barrel. Upon completion of injection,the boot contacts the deformable base, and upon application of force atthe plunger, moves the base downward, initially breaking the liquidtight seal between the base and the barrel. Continued application offorce causes the sacrificial supports within the needle assembly tosever, permitting the deformable base to move the enlarged head of theneedle downward until further movement of the enlarged head is blockedby the passageway in the needle assembly. With the enlarged needle headblocked by the passageway, continued force at the plunger causes thedeformable base to move around the enlarged needle head. As thedeformable base moves forward, the enlarged needle head begins toprotrude from the deformable base and come into contact with a thin,rupturable web on the boot of the plunger. Continued force causes theenlarged needle head to penetrate the web of the boot, positioning theenlarged needle head just inside a hollow portion of the plunger. As theplunger moves the deformable (base still further, the enlarged needlehead looses contact with the deformable base, which triggers a releaseof energy from the energy storage means in the passageway, projectingthe needle into the hollow portion of the plunger. Once inside theplunger, the needle is trapped by its enlarged head within the plunger.Final movement of the plunger causes the plunger to become captured inthe barrel at the back of the syringe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 of the drawings is a cross-sectional view of the syringe ofthis invention in its operational state.

[0013]FIG. 2 of the drawings is a cross-sectional view of the syringe ofthis invention in its post-operational state.

[0014]FIG. 3 is an isolated sectional view of the needle assembly ofthis invention.

[0015]FIG. 3A of the drawings is a cross-sectional view along line 3A-3Aof FIG. 3.

[0016]FIG. 4 of the drawings is an isolated sectional view of thedeformable base.

[0017]FIG. 4A is a cross-sectional view along line 4A-4A of FIG. 4showing the cavity for the needle head and integral flexible supports.

[0018]FIG. 5 of the drawings is an elevational side view of the energystorage means.

[0019]FIG. 6 of the drawings is an elevational view of the plunger seal.

[0020]FIG. 7 of the drawings is an isolated view of the needle with itenlarged head.

[0021]FIG. 8 of the drawings is an elevational view of the needle guard,showing the needle assembly plug tethered to the tip of the needleguard.

[0022]FIG. 9 of the drawings is an isolated sectional view of theplunger boot of this invention.

[0023]FIG. 9A is a cross-sectional view along line 9A-9A of FIG. 9,showing the plunger boot.

[0024]FIG. 9B is an enlarged sectional view of the encircled area ofFIG. 9.

[0025]FIG. 10 of the drawings is an isolated sectional view of thebarrel of this invention.

[0026]FIG. 10A is a cross-sectional view along line 10A-10A of FIG. 10.

[0027]FIG. 11 of the drawings is an isolated sectional view of a plungerin accordance with this invention.

[0028]FIG. 11A is an enlarged sectional view of the encircled area ofFIG. 11.

[0029]FIG. 11B is a cross-sectional view along line 11B-11B of FIG. 11illustrating needle capturing means.

[0030]FIGS. 12, 13, and 14 of the drawings are cross-sectionalsubassembly views illustrating assembly of the needle, enlarged head,base, barrel, needle assembly, and energy storage means.

[0031]FIG. 15 of the drawings is a cross-sectional view of the plungerof this invention, showing assembly of the plunger boot and the plungerseal on the plunger.

[0032]FIG. 15A of the drawings is a partial sectional view of theplunger showing an alternative embodiment for the plunger seal.

[0033]FIG. 16 of the drawings is a cross-sectional view of the completedassembly of the syringe.

[0034]FIG. 17 of the drawings is a graph depicting the force/balancerelationship upon which the syringe operation is based.

[0035]FIGS. 18, 19, 20, 21, 22, 23, 24, 25, 26, and 26A of the drawingsare cross-sectional views of the apparatus of this invention showing thesequence of operation, after the injection cycle.

[0036]FIG. 27 of the drawings is an elevational view of the syringeprior to needle retraction.

[0037]FIG. 28 of the drawing is an elevational view of the syringesubsequent to needle retraction wherein an indicia has been revealed.

[0038]FIG. 29 of the drawings is a cross-sectional view of analternative embodiment of the syringe of this invention in itsoperational state.

[0039]FIG. 30 of the drawings is a cross-sectional view of thealternative embodiment of the syringe of this invention in itspost-operational state.

[0040]FIG. 31 of the drawings is an isolated view of an alternativeembodiment of the needle assembly of this invention.

[0041]FIG. 32 of the drawings is a cross-sectional view drawn along line32-32 of FIG. 31.

[0042]FIG. 33 of the drawings is a side view of an alternativeembodiment of the deformable base of this invention.

[0043]FIG. 34 of the drawings is a cross-sectional view drawn along line34-34 of FIG. 33.

[0044]FIG. 35 off the drawings is a side view of the needle with anenlarged head of an alternative embodiment according to this invention.

[0045]FIGS. 36, 37, 38, 39, 40, 41, 42 and 43 of the drawings aresectional views of an alternative embodiment of the syringe of thisinvention illustrating the sequence of operation after the injectioncycle.

[0046]FIGS. 44, 45, 46 and 47 of the drawings are sectional views ofembodiments of a syringe where no supports are utilized.

[0047]FIG. 48 of the drawings is a sectional view of a preferredembodiment of a syringe where no supports are utilized.

DETAILED DESCRIPTION

[0048] In accordance with this invention it has been found that asyringe may be provided for normal operation but, which completion ofnormal operation and continued movement of the plunger, results in atriggering of the needle or cannula to project such needle harmlesslyinto the plunger and body of the syringe. Once trapped inside theplunger and body of the syringe, the needle is no longer subject toaccidental pricking or poking of human tissue thus minimizing thelikelihood of transfer of contagious disease which may be carried byfluids contained on the surface of or within such needle. To preventpossible leakage of residual fluids in the needle, the syringe can besealed after use, and after such use an automatic indication is giventhat the syringe represents a biohazard. Various other advantages andfeatures will become apparent from a reading of the followingdescription given with reference to the various figures of drawing.

[0049]FIGS. 1 and 2 of the drawings illustrate the syringe 1 of thisinvention with the needle 3 illustrated in FIG. 1 in its normalpre-injection position. FIG. 2 of the drawings, however, shows the finalposition after operation of this invention wherein the needle 3 has beentrapped and rendered harmless after the injection has taken place, andthe plunger 7 has been locked within the barrel 5 of the syringe. Thesyringe 1 in accordance with this invention has relatively fewcomponents, which along with their function, will now be described withreference to the drawings in sequence beginning with FIG. 1.

[0050] The syringe 1 has a barrel 5 and a plunger 7 mounted therein. Theneedle 3 is contained within a needle assembly 9, which is fixed tobarrel 5 by ultrasonic welding means or other permanent attaching means.

[0051] Needle 3 has an enlarged head 13, generally cylindrical in shape,positioned within and engaged by deformable base 11. Enlarged head 13has a top 14, which is preferably flat and diametrically cylindrical.The top of enlarged head 13 can be concave in one embodiment. Below top14 on enlarged head 13 are a plurality of diametrically wider areas orgradually extending bands, illustrated as areas 15 and 17, which areslightly wider than top 14. The bottom portion of enlarged head 13 iscylindrically smooth and defines a contacting portion 25 for contactingthe energy storage means. By appropriately positioning the enlargedneedle head 13 within deformable base 11 for a substantially matingengagement, the geometries of top 14 and area 15 of enlarged head 13 canbe substantially mated and locked within deformable base 11 so that aliquid tight seal between needle head 13 and deformable base 11 iscreated at top 14 of enlarged head 13. As seen in FIG. 1, all ofenlarged head 13 but a portion of the bottom portion is contained withinthe deformable base.

[0052] Needle assembly 9 has contained therein energy storage means,illustrated as spring 21, within a passageway 23, which is in contactwith contacting portion 25. Deformable base 11 is positioned betweenbarrel base shelf 2 and one end of needle assembly 9 wherein supports 31of base 11 contact the end of the needle assembly.

[0053] Plunger 7 has a hollow 41 therein and has a boot 43 covering anend thereof which is fluid impermeable for forced movement of a fluid inbarrel 5 during ordinary injection. A portion of boot 43 is illustratedas having been torn by the needle head in FIG. 2, with boot web 79laying over in the front of plunger 7.

[0054] Preferably, plunger 7 has an enlarged thumb push 45 which, uponcompletion of a compression stroke is substantially locked within amating head portion 47 of barrel 5. As seen in FIG. 2 fitting plunger 7within barrel 5 also produces a sealing action between plunger seal 4and guard ring 16, preventing release of residual fluids at the back ofthe syringe, left in the needle after use. Plunger 7 has needlecapturing means 49 therein which is illustrated in FIG. 2 as preventingthe release of needle 3 from plunger 7. Also illustrated in FIG. 2 isclosing member 51, illustrated as a plug, inserted into the front ofneedle assembly 9 to prevent residual fluids which may drain from needle3, after the capture thereof, from leaking from the front of thesyringe. It is envisioned according, to this invention that variousstructures of closing members can be utilized, such as the plug as shownand also a capping member, as long as the opening left by needleretraction can be closed.

[0055] Reference will now be made to FIGS. 3 through 11B to moreparticularly illustrate the components of this invention as describedabove.

[0056]FIG. 3 is an isolated sectional view of needle assembly 9 of thisinvention. Passageway 23 is shown and is defined within needle assembly9.

[0057]FIG. 3A of the drawings is a cross-sectional view along line 3A-3Aof FIG. 3 illustrating the needle assembly 9 of this invention.

[0058]FIG. 4 is an isolated sectional view illustrating deformable base11 which defines a passage therethrough for passage of the needle head,as discussed in more detail later. Deformable base 11 is designed tosubstantially matingly engage enlarged head 13. As seen in FIG. 4 basewedge 6 is provided, below where top 14 of enlarged head 13 can fit, forproper positioning of the needle in the deformable base. Further,cylindrical barrel seals 8 are provided to create proper sealing actionbetween base 11 and barrel 5. The diameter and width of the barrel seals8 can be made to create an optimum seal, while minimizing static anddynamic friction between base 11 and barrel 5. Also illustrated in FIG.4 are supports 31, preferably formed as opposing, semicircularcantilevered beams projecting from the upper body 12 of base 11. Eachsupport 31 has an inward engaging flange 32 for engaging a lower portionof enlarged head 13 and an end of the needle assembly, as shown inFIG. 1. Needle head seal 10 is further illustrated in FIG. 4 and iswhere top 14 of enlarged head 13 can fit. The diameter and width ofneedle head seal 10 is designed to provide optimum sealing with top 14,while minimizing static and dynamic friction between enlarged head 13and base 11.

[0059]FIG. 4A of the drawings is a cross-sectional view along line 4A-4Aof FIG. 4 illustrating deformable base 11. A preferred material for base11 is an elastomer. Supports 31 are illustrated in the preferredembodiment as a pair of opposing, semicircular cantilevered beams,however, it is envisioned according to this invention that supports 31could be connected and unitary or divided up further.

[0060]FIG. 5 of the drawings is an elevational side view of the energystorage means illustrated as spring 21.

[0061]FIG. 6 of the drawings is an elevational view of plunger seal 4illustrated in one embodiment as an O-ring seal.

[0062]FIG. 7 of the drawings is an isolated view of needle 3, orcannula, with enlarged head 13. Top 14, wider areas 15 and 17, andcontactor 25 on the bottom portion are illustrated. Also illustrated inphantom is the hollow portion 16 of the needle.

[0063]FIG. 8 shows a side view of a needle guard 12, with closing member51 attached at the end thereof. Closing member 51 is attached ortethered by a breakable tab 52 which can be of plastic construction andwhich is broken to remove closing member 51. As illustrated, closingmember 51 is preferably a plug which is attached by tab 52 to the needleguard at an angle wherein tab 52 connects to closing member 51 away fromthe end of closing member 51 which can be inserted or plugged into theneedle assembly after needle retraction. As discussed above, the closingmember of this invention can be of various types, such as a cap or aplug as shown, as long as the opening left by needle retraction can beclosed. Preferably, the opening is closed off so that a liquid tightseal is obtained. The angular attachment of the closing member preferredherein and illustrated in FIG. 8 allows a person completing needleretraction to handle just the needle guard to insert the closing memberinto the needle assembly where the needle was positioned prior toretraction. Quite advantageously, this can be accomplished with theuser's hands always positioned behind the opening in the needle assemblyleft as a result of needle retraction.

[0064]FIG. 9 is an isolated sectional view of boot 43 of this invention.FIG. 9A of the drawings is a cross-sectional view along line 9A-9A ofFIG. 9 illustrating boot 43. FIG. 9B is an enlarged sectional view ofthe encircled area of FIG. 9. Referring to FIGS. 9, 9A and 9B, a thin,rupturable web 79 is shown as a portion of boot 43. To aid in therupturing process of the web, tear groove 26 and tear groove 28, shownin FIG. 9B, are provided. The thickness of web 79 and the tear groovesare selected to withstand normal operating pressures within syringe 1,as shown in FIG. 1, but to allow relative ease in the puncturing of web79 by enlarged needle head 13, shown in FIG. 6. The preferred materialfor boot 43 is an elastomer.

[0065]FIG. 10 is an isolated sectional view of barrel 5. FIG. 10A of thedrawings is a cross-sectional view along line 10A-10A of FIG. 10 showingfinger support flange 81 of barrel 5 of this invention. Referring toFIGS. 10 and 10A, at the finger support flange 81 of barrel 5 is shownan undercut 47 for locking the plunger into the barrel. At the oppositeend of barrel 5, base shelf 2 and nose shelf 14 are illustrated. Theseinternal offsets receive the base and the needle assembly respectively.

[0066]FIG. 11 of the drawings is an isolated sectional view of plunger 7in accordance with this invention. Capturing means 49 is illustrated.Plunger boot termination 16 is also illustrated and is designed toreceive rupturable boot 43.

[0067]FIG. 11A is an enlarged sectional view of the encircled area ofFIG. 11 and illustrates cavity 30 for receiving plunger seal 4 andinclined surface 18 for fitting and substantially locking the plungerinto the body of the syringe.

[0068]FIG. 11B is a cross-sectional view along line 11B-11B of FIG. 11further illustrating needle capturing means 49.

[0069] Given the components described above, assembly in several primarysteps is required to produce the syringe. FIGS. 12 through 16 illustratethese steps so as to result in a finished product. Needle 3 is firstinserted into enlarged head 13. With reference to FIG. 12, the firstassembly step is accomplished by inserting needle 3 into deformable base11 between flexible supports 31 for a substantially mating engagement.Base wedge 6 is positioned between top 14 and wide area 15 of enlargedhead 13 which blocks needle 3 movement in both directions. A liquidtight seal between enlarged head 13 and needle head seal 10 on base 11as shown in FIG. 12 is created around the edge of top 14 of enlargedhead 13. With needle 3 blocked into base 11, the next assembly step isaccomplished.

[0070] In the next step of the assembly process, the subassembly in FIG.12 is inserted into the front end of barrel 5 as shown in FIG. 13, untilbase 11 contacts and is positioned against base shelf 2. When base 11 iscompletely inserted as shown in FIG. 13, base 11 is compressedcircumferentially in the direction of needle head 13, and a liquid tightseal is produced between base 11 and barrel 5.

[0071] To complete assembly of needle assembly 9 with barrel 5, as shownin FIG. 14, the energy storage means is first placed into passageway 23.The preferred embodiment of energy storage means is spring 21. Needleassembly 9 is then fixed to barrel 5 by threading needle 3 through thecenter of spring 21 in passageway 23 and inserting needle assembly 9into the front of barrel 5, until needle assembly 9 contacts and ispositioned against nose shelf 14. Permanently joining needle assembly 9and barrel 5 can be accomplished by ultrasonic welding around thecircumference of barrel 5 at overlap 81, or any other permanentattaching means can be utilized. Attachment of needle assembly 9 tobarrel 5 creates a liquid tight seal between the two parts. As a resultof this assembly step, the end of needle assembly 9 is positioned justin contact with engaging flanges 32 of supports 31, thus preventingmovement of base 11 and needle 3 contained therein for normal syringeuse.

[0072] In the final step of assembly, plunger seal 4 and boot 43 areplaced onto plunger 7 as shown in FIG. 15. Boot 43 is preferably placedonto plunger 7 so that web 79 is just at the end of the plunger. Plunger7 is then inserted into barrel 5. FIG. 15A is a partial sectional viewof the end of the plunger with a plunger seal showing an alternativeembodiment wherein the plunger seal is formed as an integral and unitarypart of the plunger so that the seal as provided by use of an O-ring isaccomplished by forming the ring as an integral part of the plunger. Tocomplete the assembly as shown in FIG. 16, needle guard 12 is placed onneedle assembly 9, with closing member 51 tethered at the tip of needleguard 12. It will be apparent to those in the art that there existsother possible sequences of assembly other than those described hereinthat can be used to produce the completed assembly as shown in FIG. 16,producing the same syringe ready for operation.

[0073] The syringe operates on a “force/balance” principal as depictedin the graph of FIG. 17. In the graph normal operation is represented byregions I and II. In these regions limited positive and negative forcesare applied between the plunger 7 and body 5, shown in FIG. 18, fornormal operating functions of filling the syringe and for injections.Positive forces are defined as forces which move the plunger into thesyringe body, while negative forces are defined as those forces whichpull the plunger from the syringe body. Typical “filling” and“injection” cycles are depicted in regions I and II, respectively. Aslong as the positive force applied between the plunger 7 and body 5 ofsyringe 1 is below threshold 34, base 11 balances the operating forceand remains in its assembled position, as shown in FIG. 18. But, forpositive forces applied to the syringe above threshold 34, base 11becomes unbalanced and begins to move in the direction of needleassembly 9. Once force above threshold 34 is applied and maintained,operation of the syringe moves into region III, where the needle isretracted into the plunger of the syringe. In region III, points 83, 85and 87 represent a typical device where base 11 first begins to move,needle head 13 is released and plunger 7 becomes substantially lockedinto body 5 respectively.

[0074] The sequence of operation will now be described with regard toFIG. 1 and FIGS. 18 through 28. As can be seen, FIG. 1 is across-sectional view of safety syringe 1. For normal syringe operatingforces, safety syringe 1 operates as any conventional syringe. For use,the syringe is filled from an ampule in a normal manner, as standardprocedure dictates. Once filled, the injection cycle is accomplished,again according to standard practice. At completion of the injectioncycle, plunger boot 43 is just mating with base 11, as shown in FIG. 18,and all fluids, which can be, are expended from syringe 1 through theneedle. Before the syringe is released or discarded, by the user, theneedle retraction cycle should be accomplished.

[0075] At the beginning of the needle retraction cycle, syringe 1 isusually held between the index finger and the middle finger at supportflange 81, with the thumb resting on thumb push 45, presumably the sameas the syringe was held at completion of the injection cycle. Plunger 7is contacting base 11 at boot 43, as shown in FIG. 18.

[0076] With reference to FIG. 19, force is applied between fingersupport flange 81 and thumb push 45. This force is transmitted alongplunger 7 to deformable base 11 and supports 31. As the force increasessufficiently supports 31 begin to flex open away from one another asshown in FIG. 19, wherein engaging flanges 32 move away from and losecontact with the enlarged needle head 13 and flex open just enough topass over passageway 23 and to allow further movement of base 11 andneedle 3 toward an end of the barrel.

[0077] As shown in FIG. 20, the continued application of force appliedto plunger 7 continues to cause supports 31 to ride up on and around theneedle assembly as deformable base 11 moves further. As the deformablebase and the enlarged needle head are forced toward the end of thebarrel, the bottom portion of enlarged head 13, which extends partiallyinto the needle assembly prior to the retraction process, is forcedfurther into the needle assembly, until wide area 17 contacts the end ofthe needle assembly and prevents any further movement of the enlargedhead into the needle assembly by its greater diameter than passageway 23within the needle assembly. This allows the plunger to force the base todeform and pass around the now stationary enlarged needle head. Spring21 is fully compressed in the process by contactor 25 of the needlehead.

[0078] With reference now to FIG. 21, as deformable base 11 movesfurther toward the end of the barrel, needle head 13 begins to protrudefrom base 11 and come into contact with web 79 of boot 43 on plunger 7.Continued force causes further translation of base 11 and needle head 13to tear web 79 of boot 43, positioning enlarged needle head 13 justinside hollow 41 of plunger 7 while wide area 17 remains embedded withindeformed base 11, as shown in FIG. 21.

[0079] With reference to FIG. 22, continued translation of deformablebase 11 causes wide area 17 to eventually lose contact with deformablebase 11, creating a trigger-like release of enlarged head 13. Upon thistrigger-type action, energy stored within spring 21 is released andimparted to needle 3 to project needle 3 into hollow 41 of plunger 7, asillustrated in FIG. 23.

[0080] Referring now to FIG. 24, it is seen that needle 3, at itsenlarged head 3, contacts capturing means 49 which is a flexible catchthat elastically flexes to permit enlarged needle head 13 to passthrough the constriction formed by capturing means 49 and an inner wallof plunger 7. This is further illustrated in FIG. 25 where needle head13 is shown having passed capturing means 49 and being captured withinhollow 41 of plunger 7 wherein the needle head will move back past thecapturing means. At this point, it should be noted that plunger 7 hasbeen matingly and substantially locked within barrel 5 by mating headportion 47 engaging a portion of the plunger near thumb push 45. Asshown in FIG. 26A, a liquid tight-seal between plunger seal 4 and guardring 16 is created.

[0081] To finish the operational sequence, closing member 51 tethered tothe end of needle guard 12, can be inserted into opening 22 of needleassembly 9 as shown in FIG. 26 and described with reference to FIG. 8.Closing member 51 can be forced into position by pressing it against aheavy, solid object. Once closing member 51 is lodged into position,closing member 51 can be separated from needle guard 12 with a twistingaction, leaving syringe 1 as shown in FIG. 26. This closure process cantherefore be advantageously accomplished with a user's hands alwaysremaining behind the opening left by the retracted needle.

[0082] As a result of accomplishing the needle retraction cycle asdescribed, syringe 1 is left as shown in FIG. 26. Also preferablyaccomplished during the needle retraction cycle is revelation andamplification of an indicia or label such as biohazard label 24, asshown in FIG. 28. Before the needle retraction cycle, base 11 is underbiohazard label 24 as seen in FIG. 27 wherein the label is not readable.It is preferred that biohazard label 24 be printed in black, or anyother appropriate color, and that base 11 also be the same orsubstantially similar color so that biohazard label 24 is unnoticeableto the user. It is also preferred that boot 43 be of a different,contrasting color. After the needle retraction cycle, base 11 is nolonger left under the biohazard label, and boot 43 is under the label,as shown is FIG. 28. Since boot 43 is any appropriate highly contrastingcolor relative to base 11 and the biohazard label, such as orange whenthe other two are black, biohazard label 24 is significantly revealedand amplified and becomes very noticeable to the user or other people,as shown in FIG. 28.

[0083]FIGS. 29 and 30 of the drawings illustrate the syringe 101 of thisinvention with the needle 103 illustrated in FIG. 29 in its normalpre-injection position. FIG. 30 of the drawings, however, shows the netresult of this invention wherein needle 103 has been trapped andrendered harmless after the injection has taken place, and the plungerhas been locked within the barrel of the syringe. Syringe 101 inaccordance with this invention is similar to syringe 1 described aboveand has relatively few components. Components of syringe 101 that aredifferent from syringe 1 above are the deformable base, the enlargedneedle head, and the needle assembly and the barrel.

[0084] Syringe 101 has a barrel 105 and a plunger 107 mounted therein.Needle 103 is contained within a needle assembly 109, which is fixed tobarrel 105 by ultrasonic welding means or other permanent attachingmeans.

[0085] Needle 103 has an enlarged head 113 mounted within deformablebase 111. Enlarged head 113 has a wedge portion 115 and a circularflange portion 117. By appropriately positioning the enlarged head 113within deformable base 111, the geometries of the flange portion and,wedge portion of enlarged head 113 substantially lock such enlarged headportion within the deformable base, while also creating a liquid tightseal between needle head 113 and deformable base 111.

[0086] Needle assembly 109 has contained therein energy storage means,illustrated as spring 121 within a passageway 123. Enlarged needle head113 has a contacting portion 125 which contacts energy storage means121. Sacrificial supports 131 position deformable base 111 within needleassembly 109.

[0087] Plunger 107 has a hollow 141 therein and is terminated by a boot143 having a rupturable web 179, the boot being fluid impermeable formovement of a fluid in the barrel during ordinary injection. Web 179 ofboot 143 is illustrated as having been ruptured in FIG. 30.

[0088] Preferably, plunger 107 has an enlarged compression section atthumb push 145 which, upon completion of a compression stroke, is lockedwithin a mating head portion 147 of barrel 105. Plunger 107 has needlecapturing means 149 therein which is illustrated in FIG. 30 aspreventing the release of needle 103 from plunger 107. Also illustratedin FIGS. 29 and 30 is an absorption means 151, such as cotton, tocollect any fluids which may drain from needle 103 after the capturethereof.

[0089]FIG. 31 of the drawings is an isolated view of needle assembly 109of this invention. Sacrificial supports 131 and passageway 123 areillustrated in partial phantom.

[0090]FIG. 32 is a cross-sectional view along the line 32-32 of FIG. 31,further illustrating sacrificial supports 131 and passageway 123 withinneedle assembly 109.

[0091]FIG. 33 of the drawings is a side view of deformable base 111. Apreferred material for base 111 is an elastomer. As seen in FIG. 33,counterbore 173 and thrubore 175 are provided for proper positioning ofthe needle in the deformable base.

[0092]FIG. 34 is a cross-sectional view along the line 34-34 of FIG. 33further illustrating deformable base 111.

[0093]FIG. 35 of the drawings is a side view of needle 103 or cannula.Contactor 125, circular flange 117 and enlarged head 113 with wedgeportion 115 are illustrated. Also illustrated in phantom is the hollowportion 116 of the needle.

[0094] The sequence of operation of syringe 101 will now be describedwith regard to FIG. 29 and FIGS. 36 through 43. As can be seen, FIG. 29is a cross-sectional view of safety syringe 101. For normal syringeoperating forces safety syringe 101 operates as any conventionalsyringe. For use, the syringe is filled from an ampule in a normalmanner, as standard procedure dictates. Once filled, the injection cycleis accomplished, again according to standard practice. At completion ofthe injection cycle, plunger 107 is just mating with base 111, as shownin FIG. 36, and all fluids, which can be, are expended from syringe 101.Before the syringe is released, or discarded, by the user, the needleretraction cycle should be accomplished.

[0095] At the beginning of the needle retraction cycle, syringe 101 isusually held between the index finger and the middle finger at supportflange 181, with the thumb resting on thumb push 145, presumably thesame as the syringe was held at completion of the injection cycle.Plunger 107 is just mated with base 111 at boot 143, as shown in FIG.36.

[0096] With reference to FIG. 37, force is applied between fingersupport flange 181 and thumb push 145. This force is transmitted alongthe plunger to deformable base 111 and sacrificial supports 131. As theforce increases sufficiently, the liquid tight seal between barrel 105and deformable base 111 is broken, and sacrificial supports 131 begin tofracture.

[0097] As shown in FIG. 38 further force is applied at plunger 107.Sacrificial supports 131 are severed and deformable base 111 movesforward, further compressing energy, storage means 121. Deformable base111 moves forward until circular flange 117, on needle head 113 which isin translation with base 111, comes into contact with the end of needlepassageway 123.

[0098] With reference now to FIG. 39 enlarged needle head 113 is blockedby passageway 123, and continued force at plunger 107 causes deformablebase 111 to deform and move around circular flange 117 on enlargedneedle head 113 as deformable base 111 moves forward, enlarged needlehead 113 begins to protrude from base 111 and come into contact withrupturable web 179 of boot 143, positioning enlarged needle head 113just inside hollow 141 of plunger 107 while circular flange 117 remainsembedded within deformed base 111, as shown in FIG. 39.

[0099] With reference to FIG. 40, continued translation of deformablebase 111 causes circular flange 117 to eventually lose contact withdeformable base 111, creating a trigger-like release of circular flange117. Upon this trigger-type action, energy stored within spring 121 isreleased and imparted to needle 103 to project needle 103 into hollow141 of plunger 107, as illustrated in FIG. 41.

[0100] Referring now to FIG. 42, it is seen that needle 103, at itsenlarged head 113, contacts capturing means 149 which deforms to permitenlarged head 113 to pass through the constriction formed by capturingmeans 149. This is further illustrated in FIG. 43 where needle 103 isshown captured within hollow 141 of plunger 107. At this point, itshould be noted that plunger thumb push 145 has been locked within themating section 147 of barrel 105. As syringe 101 is tilted downward,fluids remaining in needle 103 flow within hollow 141, down the exteriorside of passageway 123 to absorbent means 151 where the fluids areabsorbed and prevented from being released from the interior of syringe101.

[0101]FIGS. 44 and 45 of the drawings illustrate syringe 1 of thisinvention wherein the flexible supports are not utilized. It has beenfound according to this invention that syringe 1 can function to retractthe needle without supports 31 when small syringes, such as 1 ccsyringes are used.

[0102]FIGS. 46 and 47 of the drawings illustrate syringe 101 of thisinvention wherein sacrificial supports 131 are not utilized. It has beenfound according to this invention that syringe 101 can function toretract the needle without sacrificial supports 131 when small syringes,such as 1 cc syringes, are used.

[0103]FIG. 48 of the drawings illustrates a preferred embodiment of asyringe 161 according to the present invention where no flexible orsacrificial supports are utilized. This embodiment is particularlysuitable for small syringes, such as 1 cc, and includes a cylindricaldeformable base 163 having a central passage therethrough which matinglyengages a cylindrical enlarged needle head 165 which is attached to anend of hollow needle 167. A needle assembly 169 is attached to an end ofbarrel 171 opposite an end for insertion of plunger 173. Needle 167passes through a passageway defined through needle assembly 169, and anenergy storage means such as spring 173 is positioned within thepassageway. Enlarged needle head 165 includes two cylindrical sectionsof different diameters with the larger section being held entirelywithin base 163 prior to initiation of needle retraction and the lowercylindrical section extending partially into the needle assembly andhaving a contacting portion 175 on an end thereof for contacting spring173. Base 163 is biased in position by spring 173 against shelf 177 andby friction from barrel 171 prior to initiation of needle retraction.

[0104] Needle ejection through web 179 of boot 181 occurs as discussedwith reference to syringe 1 above, which is incorporated herein, withbase 163 being forced downwardly around the needle assembly except nosupports are utilized. As base 163 moves downwardly, the enlarged needlehead tears web 179, and when enlarged needle head 165 loses contact withbase 163, needle 167 is ejected into plunger 7.

[0105] It is thus seen that this invention provides a novel syringeapparatus which minimizes the likelihood of accidental puncture, isoperable by a single hand and which upon completion of injectionraptures the utilized needle and renders such harmless within theplunger and body of the syringe. As various other advantages andfeatures will become apparent to those of skill in the art from areading of the foregoing description which is exemplary in nature, suchmodifications and variations are embodied within the scope of thisinvention as defined by the following appended claims.

In the claims:
 1. A syringe apparatus comprising: a barrel; a plungermovable within said barrel; a needle assembly attached to an end of saidbarrel and defining a passageway therethrough; a deformable basepositioned within said barrel adjacent said needle assembly and defininga passage therethrough; flexible supports included on said deformablebase; energy storage means within said passageway; a hollow needlepassing through said passageway; an enlarged head on said needle engagedwithin said passage of said deformable base; and a rupturable web on anend of said plunger for moving a fluid within said barrel through thehollow of said needle when said plunger is moved through said barreltoward said needle assembly; whereby when said plunger moves throughsaid barrel toward said needle assembly, a fluid can be moved from saidbarrel through the hollow of said needle, and continued movement of saidplunger flexes said supports and moves said deformable base downwardlyuntil such time as sufficient force is imparted to said rupturable webby said enlarged head of said needle to tear said rupturable web, saiddeformable base then releasing said needle with said enlarged head dueto force applied thereto by said energy storage means to project saidneedle with said enlarged head into the interior of said plunger.
 2. Theapparatus according to claim 1 wherein said enlarged head is generallymatingly engaged by said deformable base.
 3. The apparatus according toclaim 1 wherein said plunger is hollow on the interior thereof forreceipt of said needle and said enlarged head and further comprisingmeans within said plunger for capturing said enlarged head of saidneedle when it is projected thereinto.
 4. The apparatus according toclaim 1 wherein said energy storage means is a spring.
 5. The apparatusaccording to claim 1 wherein said flexible supports constitute an end ofsaid deformable base and each includes an engaging flange on an endthereof.
 6. The apparatus according to claim 5 wherein said deformablebase is fitted against a shelf defined within said barrel at an end ofsaid deformable base opposite said flexible supports.
 7. The apparatusaccording to claim 1 wherein said flexible supports contact an end ofsaid needle assembly.
 8. The apparatus according to claim 1 wherein saidrupturable web is part of a boot positioned over said end of saidplunger.
 9. The apparatus according to claims 1 or 3 wherein saidrupturable web comprises at least one tear groove.
 10. The apparatusaccording to claim 1 wherein said enlarged needle head comprises a flatand diametrically cylindrical top.
 11. The apparatus according to claim1 wherein said enlarged needle head comprises a top having a concavesurface.
 12. The apparatus according to claims 1 or 10 wherein saidenlarged needle head is generally cylindrical and includes a pluralityof areas diametrically wider than a remainder of said enlarged needlehead.
 13. The apparatus according to claim 1 wherein said needleassembly is attached to said barrel whereby said needle assemblypartially extends into said barrel.
 14. The apparatus according to claim13 wherein said plunger has an enlarged operating head which is matinglyreceivable within an end of said barrel opposite said needle assembly.15. The apparatus according to claim 1 further comprising a plunger sealfor providing a liquid impervious seal between said plunger and saidbarrel at an end of said barrel opposite said needle assembly when saidoperating head of said plunger is received within said barrel.
 16. Theapparatus according to claim 15 wherein said plunger seal is an O-ringpositioned within a groove on said plunger.
 17. The apparatus accordingto claim 1 further comprising a needle guard positioned over said needleassembly.
 18. The apparatus according to claim 17 further comprising aclosing member for attachment to an end of said needle assembly toprovide a liquid impervious seal therebetween, and wherein said closingmember is removably attached to an end of said needle guard at an anglewhereby said closing member can be attached to said needle assembly andremoved from said needle guard without handling said closing member. 19.The apparatus according to claim 1 wherein said barrel has indiciathereon which is positioned above said deformable base when saidrupturable web is intact.
 20. The apparatus according to claim 19wherein said indicia and said deformable base are of substantiallyidentical colors.
 21. The apparatus according to claim 20 wherein saidboot is a contrasting color to a color of said indicia.
 22. Theapparatus according to claim 1 further comprising means for revealing anindicia on said barrel.
 23. A syringe apparatus comprising: a barrel; ahollow needle extending from an end of said barrel; a plunger movablewithin said barrel for moving a fluid out of said barrel through saidneedle; said plunger receivable within an end of said barrel oppositesaid needle; and a seal for providing a liquid impervious seal betweensaid plunger and said barrel approximately at an end of said barrelopposite said needle.
 24. The apparatus according to claim 23 whereinsaid seal is an O-ring positioned within a groove defined on saidplunger.
 25. The apparatus according to claim 23 wherein said seal is aring formed integrally as a part of said plunger.
 26. A syringeapparatus comprising: a barrel having an indicia thereon; a hollowneedle extending from an end of said barrel; a plunger movable withinsaid barrel; and means for making said indicia readable by movement ofsaid plunger within said barrel.
 27. The apparatus according to claim 26wherein said barrel is generally transparent and said means for makingsaid indicia readable comprises moving a component associated with saidplunger of contrasting color to a color of said indicia below saidindicia by movement of said plunger to make said indicia readable.
 28. Asyringe comprising: a barrel having a first end and an opposite secondend; a plunger having a forward end and movable within said barrel fromsaid second end of the barrel towards said first end, the plunger havinga hollow interior communicating with said forward end; a deformable basewithin said barrel intermediate said first and second end; a hollowneedle having a pointed front, said needle extending through said firstend of said barrel and a rear end received within and supported by saiddeformable base; energy storage means positioned in said barrel betweensaid first end said deformable base and in engagement with said needle;and a rupturable web on said forward end of the plunger; wherein a fluidcan move from within said barrel through said needle as said plungermovers through said barrel to said deformable base, and when saidrupturable web contacts said deformable base, continued movement of saidplunger moves said deformable base toward said first end, said rear endof said needle thereby tearing said web wherein said rear end losescontact with said deformable base to allow said energy storage means toeject said needle into said interior of said plunger.
 29. The apparatusaccording to claim 28 wherein said deformable base comprises flexiblesupports at an end thereof closest to said first end of said barrel. 30.The apparatus according to claim 29 further comprising a needle assemblyattached to said first end of said barrel, said needle passingtherethrough, and wherein said flexible supports are positioned againstan end of said needle assembly opposite said pointed front prior toneedle ejection.
 31. The apparatus according to claim 30 wherein saiddeformable base and said needle assembly are of sizes so that saidflexible supports can flex to surround said needle assembly and saidneedle assembly can pass within said deformable base as said deformablebase moves toward said first end.
 32. A process for retracting a needleupon completion of subcutaneous injection with a hypodermic syringecomprising the steps of: forcing a plunger of a syringe downwardlywithin said syringe to force a deformable base engaging a head of saidneedle downwardly around said head; forcing an end portion of said headto tear a base portion of said plunger; and propelling said needle intoa hollow of said plunger.
 33. The process according to claim 32 whereinsaid deformable base includes flexible supports and wherein saidflexible supports are forced to flex away from one another prior toforcing said deformable base downwardly around said head.
 34. Theprocess according to claim 33 wherein said flexible supports are forcedagainst a needle assembly through which said needle passes to force themto flex and wherein said supports flex just enough to pass around saidneedle assembly.
 35. The process according to claim 32 furthercomprising capturing said needle within said hollow.
 36. The processaccording to claim 32 further comprising sealing said plunger and saidsyringe to provide a liquid impervious seal to prevent any liquidstherein from exiting.
 37. The process according to claim 32 furthercomprising revealing a predetermined indicia on said syringe after saidneedle has been propelled into said hollow.
 38. A process for plugging apassage left open by needle ejection in a syringe comprising the stepsof: providing a syringe having a passage with an opening left open byneedle ejection; providing a needle guard for covering said needle priorto needle ejection, said needle guard having a closing member forclosing and sealing said passage opening attached thereto at an angle;sealing off said passage opening by grasping said needle guard andattaching said closing member to said passage opening; and removing saidneedle guard from said closing member.
 39. The process according toclaim 38 wherein the step of sealing off said passage opening isaccomplished wherein a user's hands and fingers remain behind saidpassage opening.
 40. A process for retracting a needle at the completionof subcutaneous injection with a hypodermic syringe, comprising thesteps of: forcing a plunger of said syringe downwardly to force a needlesupport deformable base downwardly and sever sacrificial supports;forcing an end portion of said needle to tear a base portion of theplunger; and propelling said needle into a hollow of said plunger suchthat said needle is contained entirely within said plunger.
 41. Asyringe comprising: a barrel having a first end and an opposite secondend; a plunger having a forward end and movable within the barrel fromthe second end of the barrel towards the first end, the plunger having ahollow interior communicating with the forward end; a deformable basemounted within the barrel intermediate the first and second end;sacrificial supports in the barrel for supporting the deformable basewithin the barrel; a hollow needle having a pointed front, extendingthrough the first end of the barrel and a rear end received within thedeformable base; energy storage means positioned in the barrel betweenthe first end and the deformable base and in engagement with the needle;and a rupturable boot on the forward end of the plunger; whereby a fluidis moved from within the barrel through the needle as the plunger movesthrough the barrel to the deformable base, and when the rupturable bootcontacts the deformable base, continued movement of the plunger movesthe deformable base toward the first end, the rear end of the needlethereby causing the boot to tear and losing contact with the deformablebase to allow the energy storage means to eject the needle into theinterior of the plunger.
 42. A syringe apparatus comprising: a barrel; aplunger movable within said barrel; a needle assembly attached to an endof said barrel and defining a passageway therethrough; a deformable basepositioned within said barrel adjacent said needle assembly and defininga passage therethrough; energy storage means within said passageway; ahollow needle passing through said passageway; an enlarged head on saidneedle engaged within said passage of said deformable base; and arupturable web on an end of said plunger for moving a fluid within saidbarrel through the hollow of said needle when said plunger is movedthrough said barrel toward said needle assembly; whereby when saidplunger moves through said barrel toward said needle assembly, a fluidcan be moved from said barrel through the hollow of said needle, andcontinued movement of said plunger moves said deformable base downwardlyuntil such time as sufficient force is imparted to said rupturable webby said enlarged head of said needle to tear said rupturable web, saiddeformable base then releasing said needle with said enlarged head dueto force applied thereto by said energy storage means to project saidneedle with said enlarged head into the interior of said plunger. 43.The apparatus according to claim 42 wherein said enlarged needle head iscylindrical.
 44. The apparatus according to claim 42 wherein saiddeformable base is cylindrical.